(1) Field of the Invention
This invention is concerned with machines for lasting side portions of shoes.
(2) Prior Art
Machines for lasting side portions of shoes comprise a shoe support arrangement by which a last carrying a shoe upper and an insole can be positioned and which includes means to position the shoe in a desired relationship with the longitudinal center line of the machine, instrumentalities for operating on side portions of a shoe supported by the shoe support arrangement, and means for effecting relative movement between the shoe support arrangement and said instrumentalities in a direction extending lengthwise of a shoe supported by the shoe support arrangement, whereby the instrumentalities are caused to operate progressively along opposite side portions of such shoe. One such machine is described in detail in U.S. Pat. No. 3,849,817, and in such machine instrumentalities in the form of two lasting rolls, each rotatable about an axis extending widthwise of the bottom of a shoe supported by the shoe support arrangement and each being provided with a wiping element disposed helically about the circumference thereof, are provided and also instrumentalities in the form of two adhesive applying nozzles, the arrangement being such that, as relative movement is effected between the shoe support arrangement and said instrumentalities as aforesaid, adhesive can be applied progressively by said nozzles along opposite side portions of the shoe between lasting marginal portions of the upper and corresponding marginal portions of the insole thereof, the application of adhesive as aforesaid preceding the operation of the lasting rolls by which the upper is drawn about the last and the lasting marginal portions thereof pressed against corresponding marginal portions of the insole, to which they thus become secured by the applied adhesive.
In this prior art machine, the lasting rolls are arranged to be positioned symmetrically at opposite sides of the longitudinal center line of the machine, the dimension of each roll in a direction widthwise of the shoe being operated upon being sufficient to ensure that the edge contour of each side of the shoe bottom can be accommodated without the need for any widthwise shifting of the roll during the operating cycle. In practice, the rolls are spaced apart from one another by a distance sufficient to ensure that, where the shoe bottom being operated upon is provided with a metal shank, the rolls will not foul on such shank in lasting the shank region of the shoe bottom.
Whereas the aforementioned arrangement has proved satisfactory with a majority of shoe bottoms to be lasted, nevertheless the bottoms of shoes of certain styles are so shaped that they cannot be effectively and reliably lasted when the lasting rolls are in a fixed position widthwise of such shoe bottom. Thus, for example, it may be that the forepart portion of such shoe bottom is so offset from a line passing through the shank region, which line is utilized for initially positioning the shoe in the machine, that the lasting roll for operating on the "outside" of the shoe bottom shape will not adequately cover the lasting marginal portions of the upper to be lasted, or indeed may fail to engage with the shoe bottom at all as relative heightwise movement is effected between the rolls and shoe bottom to bring them into engagement with one another at the start of a machine cycle. Again, in certain shoe styles where the shank region is very narrow, positioning the shoe with the longitudinal center line of its shank region coincident with the longitudinal center line of the machine may give rise to the lasting roll operating on the "inside" of the shoe bottom failing to engage the lasting margin portions of the shoe upper as it tracks along the shank region.
With a view to overcoming the above difficulties, it has already been proposed as suggested in U.S. Pat. No. 3,591,878, to move the side lasting rolls widthwise of the shoe bottom, as the rolls are caused to operate progressively along the sides thereof, according to the edge contour of the shoe bottom. In order to achieve such widthwise movement, however, it is necessary to provide guide means, e.g. in the form of a template, and of course a different template is required for each shoe style, this giving rise to storage problems. Furthermore, either the machine has to be provided with a grading mechanism so as to enable a single style template to be used or a size range, or alternatively a plurality of templates are required for each style to cover the range of sizes.
Again, in the first-mentioned machine, nozzles, which are mounted for movement, independently of one another, in a direction extending widthwise of the bottom of a shoe supported by the shoe support arrangement, are located adjacent one another, symmetrically at opposite sides of the longitudinal center line of the machine, at the start of an operating cycle thereof, and thereafter, when relative heightwise movement has been effected between the nozzles and the shoe bottom to bring them into engagement with one another, the nozzles are moved outwardly to a position determined by the edge contour of the shoe bottom, prior to relative movement being effected, in a direction extending lengthwise of said shoe bottom, between the shoe support arrangement and the nozzles, thus to cause adhesive to be applied progressively as aforesaid. Where, however, the foreport portion of the shoe bottom is significantly offset from the longitudinal center line of the shank region of the shoe bottom, the problem may arise that, with the nozzles adjacent one another as aforesaid, the nozzle which is to apply adhesive along the "outside" of a the edge contour may either engage the lasting margin of the upper as the nozzle contacts the shoe bottom, or even miss the shoe bottom entirely. Furthermore, in said machine the positioning of the nozzles adjacent one another as aforesaid is achieved by stop means which limits the movement of each nozzle inwardly towards the other, the arrangement being such that the nozzles are thus unable to cross the longitudinal center line of the machine as they are caused to follow the edge contour of the shoe bottom being operated upon. Where the shoe bottom contour is exaggerated, however, it may be necessary especially for the nozzle which operates along the "inside" of the shoe bottom to cross said longitudinal center line of the machine.
In U.K. Pat. No. 1,454,939 a support arrangement for supporting two cement applying nozzles is disclosed, said arrangement comprising a support mounted for pivotal movement about a vertical axis between a first, centralized position and a selected one of two second, offset positions, the arrangement being such that, at the start of an operating cycle of the machine, the support is moved from its first position to one of its second positions (selected according to whether the shoe to be operated upon is a left or a right) prior to the nozzles being located against the insole of such shoe, and thereafter, during the course of the operating cycle, the support is allowed to move freely between its two second positions according to the edge contour of the shoe bottom. Furthermore, the nozzles are mounted on said support for movement, independently of one another, in a direction extending widthwise of the shoe bottom, such movement of the nozzles, towards each other, being limited by stop means, which thus serve to position the nozzles adjacent one another for the start of the operating cycle. In this case, however, the stop means are not withdrawn after the nozzles are located in contact with the insole of a shoe to be operated upon, so that any movement of one of the nozzles across the longitudinal center line of the machine must be accommodated by movement of the support; hence the need for the support to pivot freely during the operating cycle. Such an arrangement is clearly complicated insofar as it requires stop means for the nozzles as well as centralizing means for positioning the support in its first position. In addition, allowing the support to pivot freely during the operating cycle restricts the uses to which such support can be put; e.g. it could not thus be used to support lasting rolls.
It is the object of the present invention to provide an improved machine for lasting side portions of shoes, in the operation of which machine the aforementioned disadvantages are overcome and the range of shoe styles which can be operated upon is thus extended.